The parachutelike membranes of Africa's scaly-tailed flying squirrels differ from those of the flying squirrels in the family Sciuridae because they are attached to a cartilage rod at the elbow instead of the wrist.
(A) because they are attached to a cartilage rod at the elbow instead of
(B) because of being attached to a cartilage rod at the elbow rather than at
(C) in their attachment to a cartilage rod at the elbow instead of being attached at
(D) in that they are attached to a cartilage rod at the elbow rather than at
(E) in their being attached to a cartilage rod at the elbow instead of
答案是D 我认为是B
但是我觉得以前og里做到类似题目时说in that是wordy，现在却又说because of being是wordy
我不懂~~ 而且我认为D中they 指代会有歧义啊！！ 求问~~~~~ | 
